DESCRIPTION: (Investigator's Abstract); In alternative medicine, pancreatic enzymes have a long and controversial history, dating back to the nineteenth century. The primary objective of this proposal is to determine whether enzyme therapy, is an effective means of inhibiting the growth of a primary mammary tumor and its dissemination to a distant organ.To this end, clone MTLn3 derived from the R-13762 metastasizing mammary tumor will be used as a model for human breast cancer metastasis. Tumor cells will be inoculated orthotopically, i.e. into the mammary fat pad, into two groups of F-344 female rats: (1) young virgins aged 6-9 weeks (premenopausal model) and (2) retired breeders aged 40-45 weeks (postmenopausal model). The two groups will be subdivided into four subgroups and a dehydrated porcine pancreatic preparation fed during the light cycle at 3.5, 2, 1 and 0 gms/day to 12 rats per group, respectively. After 40 days, all animals will be sacrificed and growth of the primary tumors and pulmonary metastases enumerated. The pancreative preparation, as well as dose and time of feeding are based, by extrapolation, on the clinical studies of Dr. N. Gonzalez who is a co-investigator on this proposal. The significance of this study is threefold.First, it involves experimental validation of an alternative medical procedure which, though used in the clinic, has not been tested by accepted scientific methods. Second, it provides a collaboration between a practitioner of alternative medicine and an experienced cancer researcher. Third, if successful, it will provide the basis for a clinical trial based on accepted scientific methods.